Forum Discussion

Bill_Carson's avatar
Bill_Carson
On our wavelength
5 years ago
Solved

SYNC Timing Synchronization failure - Loss of Sync

Hi All,

 

first post here, and its for syc timing errors. this issues started a few days ago , the internet was cutting out and then coming back. i have rebooted all the kit. switched it off for 10 mins and then turned it back on etc etc. still getting the same issue. called VM and the automated system said they needed to send a signal to the kit, did that and it rebooted everything. still same issue.

Network Log:

Time

Priority

Description

22/06/2020 10:35:56

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

22/06/2020 10:35:56

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

22/06/2020 09:00:45

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

22/06/2020 06:41:17

Error

DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 23:10:52

Error

DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 18:03:14

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 17:58:32

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 17:28:4

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 15:40:31

Error

DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 09:14:47

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 09:13:50

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 08:22:22

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

21/06/2020 00:39:48

Error

DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

20/06/2020 21:58:27

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

20/06/2020 21:58:27

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

20/06/2020 21:57:0

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

20/06/2020 21:18:8

critical

SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

20/06/2020 21:16:36

Warning!

RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

 

 

dropout
SYNC Timing
  • Roger_Gooner's avatar
    Roger_Gooner
    5 years ago

    It obviously isn't a WiFi problem. Can you check that all your coax connections are tight?

  • Andrew-G's avatar
    Andrew-G
    5 years ago

    Synchronisation failure is where the hub can't maintain a lock on one or more of the 28 channels it uses to connect with the gear in the street cabinet.  And when it does lose synch, that loss of one or more channels becomes a "partial service".  What that means for the customer is slowdowns, disconnection and poor latency.  The hub does try and renegotiate the lost channel, but that takes time, and the problem will recur.

    The underlying cause is usually noise on the upstream, because it is those channels that the hub uses to communicate with the gear in the street cabinet.  The upstream looks OK on the data you've posted, but that's most likely because you've recently rebooted the hub (I can tell that from the low error counts).  Rebooting causes the hub to renegotiate all 28 channels, and usually provides a temporary fix, but because the underlying cause isn't fixed, it will recur.  Replacing the hub won't make a blind bit of difference - that's a cheap fix by agents who know nothing about the technology.  If they'd looked at your network log and knew what it meant they'd have sent out a technician to find the real problem.  

    You can try dialling it in, but chances are you'll get more of a run around by the utter clowns that VM use as offshore technical support.  Better to wait (maybe a day or two) for the UK based VM forum staff to get round to this post and advise on next steps.  They're usually very helpful, but don't accept the excuse "I've had a look and everything appears OK from our side" - the Network log is crystal clear on the fault and the impact on your service, and that's been recorded by VM's own equipment.  You need a technician.

  • Andrew-G's avatar
    Andrew-G
    5 years ago

    There's no harm in plugging in the replacement hub (other than the inconvenience of setting it up, getting it activated, and reconnecting all your wireless devices).  And at least you've then gone along with VM's initial (if misguided) effort to resolve the problem.  Who knows, MAYBE it will work, I just don't expect it to.

    If/when it doesn't work then VM have to accept that any subsequent problems aren't down to the hub, and will have to send a technician.

102 Replies

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  • jongosling's avatar
    jongosling
    Tuning in
    2 years ago

     today’s BQM. I’ve managed to fight through the VM support and a technician will be with me Monday.

    • Megan_L's avatar
      Megan_L
      Forum Team (Retired)
      2 years ago

      Hi Jongosling,

      Thanks for using the Community Forums to get this issue with your services looked into, I am sorry if this has been causing some frustration 😥 But I am glad to hear you managed to get a technician visit for Monday.

      Can I ask how this visit went please? If you're still having issues then please let us know and we will continue to help.

      Thanks,

      Megan_L

  • Roger_Gooner's avatar
    Roger_Gooner
    Alessandro Volta
    2 years ago

    The Post RS Errors on every downstream channel shows that there is still a problem somewhere, an a tech should attend again.

  • jpeg1's avatar
    jpeg1
    Alessandro Volta
    2 years ago

    Still horrendous noise and consequent data loss on all download channels. This connection is not fit for purpose. 

    • Joseph_B's avatar
      Joseph_B
      Forum Team (Retired)
      2 years ago

      Hey jongosling,

      Thanks for getting back to us, sorry that you are still having this issue, based upon the checks we can run your system shows as fine, however we can see you are using your Hub in Modem mode, with this we are limited in what we can see from our side diagnostics wise.

      Joe

      • jongosling's avatar
        jongosling
        Tuning in
        2 years ago

        Joe,  I’ve removed the 3rd party router and returned the Hub 3.0 to router mode (including a factory reset). Please re-run the system checks as the problem persists (pictured is the 24hr window since the Hub 3.0 was reinstated as modem & router). 

         

        thanks, Jon

  • jongosling's avatar
    jongosling
    Tuning in
    2 years ago

    The dropouts continue, with exceptionally unreliable service between 6am - 12 pm.

  • jongosling's avatar
    jongosling
    Tuning in
    2 years ago

    Hi all,

    I'm also experiencing regular dropouts (<2mins of no connection from modem to VM several times every day) of service, and the VM support has been useless in resolving this (obsessed with WiFi connectivity and have sent me a WiFi pod that I didn't need / isn't the problem). The issue is clearly between modem and VM, and I have similar entries in my hub's log (Critical: SYNC Timing Synchronization failure | Critical: No Ranging Response received - T3 time-out | Warning! RCS Partial Service | Error: DHCP RENEW WARNING - Field invalid in response v4 option) are the regular offenders. I would appreciate some actual support with this issue!

    Thanks, Jon

    • Gareth_L's avatar
      Gareth_L
      Icon for Forum Team rankForum Team
      2 years ago

      Hello jongosling.

      Thanks for your post and welcome to our community.

      Sorry to hear about the regular drop outs.

      Does this happen primarily with the hub or do you have a 3rd party device set up and the hub set to modem mode?

      Gareth_L 

      • jongosling's avatar
        jongosling
        Tuning in
        2 years ago

        Hi Gareth,

        It's happened since moving into the property. I originally had the hub 3 in router mode, but the wifi signal was poor. I now used a 3rd party router with the VM Hub 3 in modem mode. There are usually at least 2 drop outs per day. PSA recent examples.

        Thanks, Jon

  • Carley_S's avatar
    Carley_S
    Icon for Forum Team rankForum Team
    2 years ago

    Thanks so much for joining me on private message ari43277 
    I have now booked you a visit for broadband issue – you can check the date and time via your online account here. If you have any issues with accessing your online account or unable to see your visit, please do let us know and we’ll pop you a message to confirm.

    There will be no charge for this visit unless:
    •    The technician diagnoses the faults as not being caused by our network/equipment 
    •    The technician discovers that the fault or problem relates to your equipment
    •    The technician discovers that the fault or problem relates to any system that we are not responsible for

    The technician will confirm during their visit if any of these instances apply, and if so, a £25 charge will be applied to your account.

    Please ensure there is someone over the age of 18 present at the time of the visit. If you need to change your appointment you can do this online or via the MyVM app by 4pm the day before the appointment.

    If you do miss an agreed appointment for any reason, a £25 missed appointment charge will be applied to your account on the day of the appointment.

     

    • KingClouds's avatar
      KingClouds
      Joining in
      2 years ago

      I think I am having a similar issue to this guy, the dropouts are intermittent and the speeds are lower than they should be considering I'm on the 350 package and I keep getting several errors but mainly the sync time out error, here's my logs for today 

      Network Log

      Time Priority Description

      11/08/2023 17:37:6noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 17:26:35criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 17:02:0noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 16:57:4criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 16:43:12noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 16:35:40criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 12:32:38Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      11/08/2023 02:50:20ErrorDHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 19:50:0criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:48:1Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:48:0Warning!Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:36:0Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:35:47noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:06:41Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:04:38noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:04:21Warning!LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 18:02:50criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 17:53:17Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 17:50:20criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      10/08/2023 17:40:40Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
      • Daniel_Et's avatar
        Daniel_Et
        Icon for Forum Team rankForum Team
        2 years ago

        Hi KingClouds, thank you for your post.

        We're sorry to hear about the problems you've been experiencing 😔

        We've had a look on our systems and they've identified a short-term issue which may cause intermittent or performance-related issues with your connection.

        These short-term issues can happen when we’re working to fix some other network issues in the area, or when we install a new home to our network.

        We apologise for any inconvenience, and as we resolve most of these types of issues within 24 hours, you should see an improvement in your connection soon.

        How long have you been experiencing the problems for?

        Regards,
        Daniel

  • dannysomekh's avatar
    dannysomekh
    Joining in
    5 years ago

    I upgraded to VM on Monday 29th July and have had major problems ever since. After much investigation it seems the issue of slow speed and outages relates to sync timings. I am looking to cancel my contract, assuming I’m in the cool off period, as I don’t have time to be given the runaround. 

    • gary_dexter's avatar
      gary_dexter
      Alessandro Volta
      5 years ago
      dannysomekh wrote:

      I upgraded to VM on Monday 29th July and have had major problems ever since. After much investigation it seems the issue of slow speed and outages relates to sync timings. I am looking to cancel my contract, assuming I’m in the cool off period, as I don’t have time to be given the runaround. 

      So you can either ask for assistance here by creating your own thread or yes cancel if you’re within 14 days

  • Bill_Carson's avatar
    Bill_Carson
    On our wavelength
    5 years ago

    Levels:

    Downstream bonded channels

    Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

    1291000000-3.740256 qam20
    2267000000-3.538256 qam17
    3275000000-3.240256 qam18
    4283000000-3.740256 qam19
    5299000000-2.938256 qam21
    6307000000-2.740256 qam22
    7315000000-2.540256 qam23
    8323000000-2.738256 qam24
    9331000000-2.740256 qam25
    10339000000-2.738256 qam26
    11347000000-2.740256 qam27
    12355000000-340256 qam28
    13363000000-2.940256 qam29
    14371000000-2.940256 qam30
    15379000000-2.940256 qam31
    16387000000-340256 qam32
    17395000000-3.238256 qam33
    18403000000-3.938256 qam34
    19411000000-4.238256 qam35
    20419000000-4.440256 qam36
    21427000000-4.240256 qam37
    22435000000-4.238256 qam38
    23443000000-4.440256 qam39
    24451000000-440256 qam40



    Downstream bonded channels

    Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

    1Locked40.340
    2Locked38.940
    3Locked40.350
    4Locked40.3120
    5Locked38.960
    6Locked40.950
    7Locked40.360
    8Locked38.950
    9Locked40.310
    10Locked38.950
    11Locked40.350
    12Locked40.360
    13Locked40.360
    14Locked40.350
    15Locked40.330
    16Locked40.350
    17Locked38.940
    18Locked38.900
    19Locked38.660
    20Locked40.350
    21Locked40.360
    22Locked38.960
    23Locked40.340
    24Locked40.950

     

    Upstream bonded channels

    Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

    1537000004.65512064 qam2
    2394000004.575512064 qam4
    3462000004.625512064 qam3
    4326000004.55512064 qam5



    Upstream bonded channels

    Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

    1ATDMA0000
    2ATDMA0000
    3ATDMA0000
    4ATDMA0000

     

     

    Another thing i have noticed, i seem to flat out at 160Mb/s download and never get the advertised 350Mb/s and thats connected to the device wired:

    https://www.speedtest.net/result/9645355882

    • Bill_Carson's avatar
      Bill_Carson
      On our wavelength
      5 years ago

      I should also add, im on the 350Mb/s service, up until now i have never really experienced any issues with my service. I am a heavy user, as i work from home well before any of this covid 19 stuff kicked off, so i need a reliable connection.

       

      i called VM helpdesk and the guy on the phone said it was a problem with the wireless portion of the hub so is sending out a new hub that will be with me on wednesday?? even though i explained to him it wasnt a wifi issue, and that i was hard wired.

      • Bill_Carson's avatar
        Bill_Carson
        On our wavelength
        5 years ago

        Network Log

        Time Priority Description

        22/06/2020 20:47:5Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
        22/06/2020 20:47:5criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;